Device for producing anastomoses and coagulation electrode

ABSTRACT

A device for producing anastomoses between first and second hollow organs, each having inner and outer surfaces. The device comprises a sleeve with an electrode arrangement, over which the first hollow organ is placed such that its inner surface comes to lie on a outermost surface of the sleeve, and an outer electrode arrangement, which can be brought into electrical contact with the opposing electrode arrangement carrying the second hollow organ, which is pushed over the first hollow organ. The outer electrode arrangement comprises a plurality of lamellae, configured and arranged such that, in a closed state, the lamellae form a through aperture and the inner edges of the lamellae lie against the second hollow organ and, in an open state, a gap is formed between the lamellae through which the hollow organs connected to one another can be guided outwardly out of the through aperture.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/059,682, filed on Feb. 18, 2011, which is the U.S. national stage ofInternational Application No. PCT/EP2009/005365, filed Jul. 23, 2009,which claims priority to German Application No. 10 2008 038 313.9, filedAug. 19, 2008 and German Application No. 10 2008 048 293.5, filed Sep.22, 2008, the entirety of which applications are herein incorporated byreference herein.

FIELD OF THE INVENTION

Embodiments of the invention relate to a device for producinganastomoses and a coagulation electrode.

BACKGROUND

An anastomosis is a connection between two anatomical structures. Forexample, blood vessels severed during an organ transplantation can beconnected to one another anastomoses.

In surgery, various methods for producing such anastomoses are known.For example, the connection can be made using suturing techniques.Inserts also exist that permit an organic connection by adhesivetechniques. In this context, fibrin glues are often used, which enablethe very advantageous connection of organs, particularly hollow organs.However, the tolerability of such adhesives is problematic, since theycan have thrombogenic and toxic properties.

Clamping techniques are also used to create a connection at a suitablesite. Various aids, such as rings, cuffs or stents are used to assist inthe production of anastomoses.

It is disadvantageous, however, that these aids usually remain in thehollow organ being connected and can cause rejection reactions orincrease the risk of thromboses.

WO 03/061487 A1 discloses connecting hollow organs by the application ofa suitable high frequency (HF) current. When the HF current is applied,biological welding of the tissue structures takes place. The cellularsubstance coagulates with the result that the protein structures adhere,so that a controlled, secure and rapid connection can be created. WO03/061487 A1 provides an instrument for the application of an HFcurrent, said instrument comprises an inner sleeve and an outer sleeve.These sleeves each comprise an electrode, which is ring-shaped, to whichthe HF current is supplied. This instrument is a bipolar HF instrument.To connect the ends of a blood vessel, the first end is guided throughthe inner sleeve and is folded over such that the tissue comes to lieagainst the outside of the inner sleeve. The second end of the vessel ispulled over the inner sleeve and the end section of the blood vesselsituated thereon. The outer sleeve can be opened and placed over theinner sleeve and the tissue situated thereon. The electrodes arearranged on the sleeves such that the first and second ends of thevessel are clamped between the electrodes on the sleeves. On applicationof the HF current, said current flows through the tissue and welds theends.

A problem with WO 03/061487 A1 lies in the fact that in order to weld orcoagulate hollow organs having different diameters, a plurality ofdifferently configured instruments is needed. In particular, the gapbetween the electrodes and the sleeves must be dimensioned so that it ismatched to the thicknesses of the walls.

Only when the electrodes are optimally placed on the tissue structuresdoes the advantageous welding of the tissue structures take place. Thecoagulation procedure requires continuous pressure on the tissuestructures or vessel end sections throughout the coagulation process.

The results finally achieved with the instrument disclosed in WO03/061487 A1 are strongly dependent on the choice of a suitableinstrument, i.e. on the judgment of the treating physician and aretherefore difficult to document and reproduce.

SUMMARY

Proceeding from this prior art, it is an object of the embodimentsdisclosed herein to provide a device for producing anastomoses betweenfirst and second hollow organs, which is simple to operate and issuitable for forming high quality anastomoses, while also avoiding theaforementioned disadvantages. A coagulation electrode suitable for thispurpose is also provided.

In particular, the problem associated with the prior art is solved witha device for producing anastomoses between first and second holloworgans, each having an inner surface and an outer surface. Said devicecomprises a sleeve with an inner electrode arrangement, over which thefirst hollow organ is placed such that the inner surface thereof comesto lie on an outermost surface of the sleeve, and an outer electrodearrangement which is situated, in particular, radially opposing theinner electrode arrangement and can be brought into electrical contactwith the second hollow organ, which is pushed over the first holloworgan, such that the electrode arrangements make contact with the outersurfaces of the hollow organs. The outer electrode arrangement comprisesa plurality of lamellae that are movable relative to one another bymeans of at least one guide member and are configured and arrangedmovable such that, in a closed state, inner edges of the lamellae form athrough aperture and lie against the second hollow organ and, in an openstate, a gap is formed between the lamellae, leading from outside to thethrough aperture, through which the hollow organs connected to oneanother can be guided outwardly out of the through aperture.

An essential concept of the embodiments described herein is that theouter electrode is formed by a plurality of lamellae, which are movablerelative to one another. The lamellae are arranged such that they areable to assume at least two states; specifically, a closed state and anopen state. In the open state, at least the lamellae are spaced apartfrom the sleeve with the inner electrode arrangement such that a throughaperture is formed, in which the relevant sections of the hollow organscan be positioned, preferably largely in the absence of tissue contactor radial force application. In the closed state, the inner edges of thelamellae lie at least partially on the hollow organ and enable directapplication of the HF current. The outer electrode arrangement with thelamellae is partable. In the open state, a gap can form, dividing thelamellae. Due to the gap, the unconnected hollow organ or vessel can beintroduced and the connected organ or vessel can be removed from thedevice.

Preferably, the lamellae can exert mechanical pressure on the holloworgans. The closing and coagulation conditions can be determinedrelatively precisely. By this, the formation of anastomoses having ahigh load-bearing capability can be ensured. Following connection of thehollow organs, the device can be easily removed in the open state.Injury to the organs or excessive loading of the created connection isavoided.

The lamellae can be adjustable such that, in the closed state, anaperture that matches the hollow organ to be treated is formed. Holloworgans with different dimensions can therefore be treated with a deviceaccording to the embodiments described herein. For example, bloodvessels with different diameters can be treated. The instrument can besuitable for connecting veins and arteries.

The lamellae can be constructed and/or arranged in the manner of an irisdiaphragm. The through aperture is therefore formed substantiallycircular. This is advantageous for a number of applications, such as theconnection of vessels. Furthermore, an iris diaphragm is particularlysuitable for providing a substantially continuous contact surface of thelamellae. A continuous application of the HF current therefore takesplace. An applied mechanical pressure can be evenly distributed over theouter surface and surfaces of the second hollow organ.

The sleeve can be arranged fixed relative to the outer electrode in aholder or mounting. The sleeve is then arranged in a predeterminedposition relative to the outer electrode. Positioning of the sleeverelative to the outer electrode is therefore dispensable. In addition,the disclosed device can be constructed substantially more compact byfixing it in a holder. Handling is simplified by the fixed or adjustablepositioning.

The mounting can be removed for individual manipulation of the sleeve.This means that the mounting can be released from the device and usedseparately therefrom. It is therefore possible, in a preparation phase,to arrange the first hollow organ and/or the second hollow organ in oron the sleeve. Then, the sleeve and the device can be coupled such thatthe sleeve is situated in an advantageous position relative to the outerelectrodes. Following the coagulation procedure, it can be advantageousto release the mounting from the device again, to avoid straining theconnected hollow organs unnecessarily.

In the closed state, the inner edges of the lamellae can be spaced atsubstantially the same distance from the sleeve. Therefore, in theclosed state, the inner edges lie against the second hollow organ,particularly on the inner surface thereof. The HF current is applieddirectly to the tissue. The achieved connection is of correspondinglybetter quality.

The diameter of the through aperture is adjustable with the movement ofthe lamellae. The device can therefore be opened and closed by movingthe lamellae.

In the open state, the gap can divide the outer electrode in two halves,which can be moved apart from one another. It is thus possible to createan iris, which can be divided, for example, into two semicircles. Thisfacilitates the safe removal of the device following a coagulationprocedure.

The sleeve can be held on an actuating device and can be configured tobe dismantled into two parts such that the parts can also be broughtfrom a closed state, forming a closed tubular section, into an openstate for removal from the hollow organ. The sleeve can therefore beconfigured in two parts, so that said sleeve can be disassembled afteror before the application of the HF current. For example, it may bepossible to spread the individual parts of the sleeve apart in to ensurebetter handling of the organs. The spreading of the sleeve can alsoprevent the hollow organ placed over the sleeve from slipping off.

In a closed state, the actuating device can be pre-tensioned. The closedstate therefore establishes itself automatically.

The lamellae can be pre-tensioned into the closed state with a definedforce by a tensioning device. Preferably, the tensioning device can beadjusted so that, in the closed state, the lamellae are pressed with apre-defined force against the hollow organs. This force not only enablesreliable coagulation of the tissue, but is also dimensioned so that thehollow organs are not damaged. By setting the tensioning device,repeatability of the treatment results can be assured.

The problem defined above is also solved with a coagulation electrode,comprising: a mounting ring; a plurality of lamellae mounted on themounting ring, said lamellae being pivotable from an open state to aclosed state, in the manner of an iris diaphragm, to form electrodesections; a linkage ring arranged rotatable relative to the mountingring and which engages with guide members on the lamellae such that onrotation of the linkage ring relative to the mounting ring, the lamellaeare pivoted from the closed state to the open state and vice versa,wherein the mounting ring and the linkage ring are each configured intwo parts such that they can be moved away from one another togetherwith the lamellae mounted on the mounting ring and engaging with thelinkage ring.

A coagulation electrode of this type has similar advantages to theaforementioned device. In particular, the coagulation electrode ispartable and is therefore easily removed after application of the HFcurrent. This means that the coagulation electrode can easily be removedfrom the connected hollow organ.

The linkage ring can also can also be a lamella and perform the functionthereof.

The linkage ring can comprise linkage ring sections that are movableseparately from one another, in particular, with guide rods.

The linkage ring can comprise exactly two linkage ring sections formingthe linkage ring. The sections can actuate the lamellae. In particular,the lamellae can be rotated relative to the mounting ring (preferablycomprising two mounting ring sections). The lamellae are brought intothe open or closed state.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described in greater detailwith reference to the drawings, in which:

FIG. 1 shows an electrosurgical instrument for producing anastomoses,with the arms opened;

FIG. 2 shows the instrument of FIG. 1 with the arms closed (and irisdiaphragm open);

FIG. 3 shows the instrument of FIGS. 1 and 2 with the arms closed (andthe iris diaphragm closed);

FIG. 4 shows a closing force adjusting device for the instrument ofFIGS. 1 to 3;

FIG. 5 shows a detailed view of a section of the iris diaphragm of FIG.1 with a positioning device;

FIG. 6 shows the iris diaphragm of FIG. 5 in an exploded view;

FIG. 7 shows a further embodiment of the lamellae for an iris diaphragm;

FIG. 8 shows a detailed view of the iris diaphragm of FIG. 1 (irisdiaphragm closed);

FIG. 9 shows a detailed view of the iris diaphragm of FIG. 1 (irisdiaphragm open);

FIG. 10 shows a detailed view of a further embodiment of an irisdiaphragm (iris diaphragm closed);

FIG. 11 shows the iris diaphragm of FIG. 10 (iris diaphragm open);

FIG. 12 shows a further embodiment of the iris diaphragm in an explodedview; and

FIGS. 13 and 14 show detailed views of the iris diaphragm of FIG. 12.

DETAILED DESCRIPTION

In the following description, the same reference signs are used forsimilar and similarly acting parts.

FIG. 1 shows an electrosurgical instrument 10 for producing anastomoses.The instrument 10 comprises a base plate 13, on which arms 12, 12′ arepivotably mounted. A closing device 20 serves to actuate the arms 12,12′. Said closing device 20 comprises a closure actuating element 24,which is connected to the arms 12, 12′ via a linkage guide. The closureactuating element 24 has essentially two positions; specifically, afirst position in which the electrosurgical instrument 10 is open and asecond position in which the electrosurgical instrument 10 is closed.Preferably, the closing device 20 is configured so that the arms 12, 12′are fixed in the second position such that unintentional opening of theelectrosurgical instrument 10 is not possible (see FIG. 2).

Situated at the distal end of the arms 12, 12′ are half diaphragms 51,51′, which form an iris diaphragm 50 in the closed state of theelectrosurgical instrument 10 (see FIGS. 2 and 3).

The electrosurgical instrument 10 also has a tensioning device 40 foractuating the iris diaphragm 50. Said tensioning device 40 comprises atensioning device actuating element 42 and a force deflector 44, whichare pivotably mounted on the base plate 13, a tensioning spring 41 andtwo actuating elements 52, 52′. The actuating elements 52, 52′ extend,respectively, along the first arm 12 and the second arm 12′ and transmitthe forces exerted by the tensioning device 40 to the mechanisms formingthe iris diaphragm 50. In the open position of the electrosurgicalinstrument 10, the tensioning device 40 is also in an open position (seeFIG. 1). In the second, closed position of the electrosurgicalinstrument 10, the tensioning device 40 can be tensioned by actuatingthe tensioning device actuating element 42. FIG. 3 shows the tensioningdevice actuating element 42 in the tensioned state. On actuation of thetensioning device actuating element 42, the tensioning spring 41 whichis connected to the force deflector 44 is tensioned. This results in arotary movement of the force deflector 44 about a pivot point situatedbetween the arms 12, 12′. The rods or actuating elements 52, 52′, whichare attached to the force deflector 44 substantially symmetrically aboutsaid pivot point, execute a translation movement in the proximal(actuating element 52′) or the distal (actuating element 52) direction.This movement leads, as described in greater detail below, to closingand opening of the iris diaphragm 50.

It should be noted that, in the tensioned state, the tensioning spring41 continuously exerts a force, via the actuating elements 52, 52′ onthe mechanisms forming the iris diaphragm 50. The value of this forcecan be adjusted with a closing force adjusting device 45 (see FIG. 3).The embodiment of the force deflector 44 as shown in FIG. 3 comprises aplurality of bores with different distances from the pivot point of theforce deflector 44. The tensioning spring 41 is configured such thatsaid spring can be anchored in the individual bores. The spring force ofthe tensioning spring 41 is therefore applied to the force deflector 44with a different leverage depending on the position in the bores. Asshown in FIGS. 1-3, the force deflector 44 extends beyond the base plate13 such that said force deflector is manually actuatable. The irisdiaphragm 50 can also be opened and closed in the non-tensioned statevia the force deflector 44, which serves as an actuating element.

FIG. 4 shows a further embodiment of the tensioning device 40. In thiscase, the closing force adjusting device 45 comprises an adjusting screw46 and an angle bracket 47. The angle bracket 47 is fastened to theforce deflector 44 such that said angle bracket can be displaced along alongitudinal axis by actuation of the adjusting screw 46. In theexemplary embodiment shown in FIG. 4, the tensioning spring 41 acts onthe angle bracket 47. By actuating the adjusting screw 46, the leverwith which the tensioning spring 41 exerts the force on the forcedeflector 44 can be adjusted in steps (i.e., stepwise adjusted).

A positioning device 30 (see FIG. 5) is another key element of theelectrosurgical instrument 10. Said positioning device comprises asleeve 32 for accommodating the hollow organs and two sleeve actuatingarms 35, 35′. The positioning device 30 essentially serves to positionthe hollow organs in the center of the iris diaphragm 50; it alsoprovides a sleeve electrode 36. The sleeve 32 is constructedsubstantially cylindrically and comprises a first sleeve section 33 anda second sleeve section 33′. In cross-section, transversely to thelongitudinal axis of the sleeve 32, the sleeve sections 33, 33′ eachform a semicircle. The sleeve sections 33, 33′ are connected to thesleeve actuating arms 35 and 35′, respectively. Said actuating arms 35,35′ are pivotably fastened to a removable section 13′ (FIG. 1) of thebase plate 13, such that the sleeve sections 33, 33′ can be opened andclosed. In the closed state, the sleeve sections 33, 33′ lie against oneanother and form the sleeve 32. The positioning device 30 can thus beopened and closed via the sleeve actuating arms 35, 35′. Preferably, aspring force which keeps the sleeve sections 33, 33′ closed is appliedto the sleeve actuating arms 35, 35′. The removable section 13′, onwhich the sleeve actuating arms 35, 35′ are pivotably mounted, isconnected to the base plate 13 via a plug-in connection. In order toaccommodate the hollow organs, the positioning device 30 can be detachedfrom the remaining components of the electrosurgical instrument 10 andindividually operated.

The partability of the sleeve 32 is particularly advantageous whenplacing the instrument 10 on, and removing the instrument from, thehollow organ. To facilitate this procedure, the sleeve 32 comprises atleast two spikes 28, which are arranged on the sleeve sections 33, 33′radially to the longitudinal axis of the sleeve 32. If the hollow organ,or the sections thereof, is pushed over the sleeve 32, the spikes 28 fixthe hollow organs or vessels that have been placed thereon. The sleeveactuating arms 35, 35′ limit the advance of said organs.

Following accommodation of the hollow organs, the removable section 13′can be reconnected to the base plate 13 and brought into a positionwhich is suitable for connecting the sections of the hollow organ.

An essential point of the disclosed embodiments lies in constructing thedevice head of the electrosurgical instrument 10 in the form of apartable iris diaphragm 50. As shown in FIG. 1, the iris diaphragm 50comprises two half diaphragms 51, 51′ which, in the closed state,cooperate as one iris diaphragm 50. The construction of a halfdiaphragm, specifically the half diaphragm 51, is illustrated in FIG. 6.Said half diaphragm comprises a fastening plate 56, which issubstantially semicircular and is firmly connected to the first arm 12.A also semicircular shell 57 extends along the outer edge of saidfastening plate 56. The shell 57 has an aperture 60 through which asickle-shaped actuating plate 54 extends into the interior of the halfdiaphragm 51. The actuating plate 54 can be actuated by the actuatingelement 52 such that said actuating plate performs a circular movementabout the center of the iris diaphragm 50. Arranged between theactuating plate 54 and the fastening plate 56 is a plurality of lamellae53, 53′, 53″, which are partially pivotably connected to the fasteningplate 56. Claws 59, 59′ on the lamellae 53, 53′, 53″ engage incorresponding lamellar linkage plates 58 in the actuating plate 54. Thelamellae 53, 53′, 53″ are configured and arranged such that theorientation of the lamellae 53, 53′, 53″ can be altered by the movementof the actuating plate 54. As FIGS. 8 and 9 show, the lamellae canassume at least two positions. The lamellae 53, 53′, 53″ have innerwalls 66, which act as electrodes. In a first position (FIG. 9), thelamellae 53, 53′ are positioned so as to hardly project beyond theactuating plate 54. A circular through aperture, into which the sleeve32 extends, is formed. Situated between the sleeve 32 and the inneredges 66 of the lamellae 53, 53′ is a gap suitable for accommodatingsections of the hollow organs.

In a closed position, the through aperture is reduced such that theinner edges 66 of the lamellae 53, 53′, 53″ lie against the sleeve 32(see FIG. 8). Insofar as tissue sections of the hollow organs aresituated between the inner edges of the lamellae 53, 53′, 53″ and thesleeve 32, they are pressed against one another and against the sleeve32 with a defined force. This force can be adjusted with the closingforce adjusting device 45 and is transferred via the actuating elements52, 52′ to the lamellae 53, 53′, 53″.

The covers 55, 55 a (FIG. 6) are alternately placed on the halfdiaphragms 51, 51′ to protect their mechanisms.

FIG. 7 shows a further embodiment of the lamellae 53, 53′. Said lamellaeare configured stepped and close to each other such that a first lamella53 not only slides over the second lamella 53′, but also engages it.

A further embodiment of the lamellae 53, 53′ is shown in FIGS. 10 and11. FIGS. 10 and 11 show the iris diaphragm 50 in a plan view, whereinthe iris diaphragm 50 is closed in FIG. 10 and is open in FIG. 11. Forthe sake of a better view of the mechanism of the iris diaphragm 50, thecover 55′ is removed in FIG. 10. It is apparent that the lamellae 53,53′ engage via T-anchors 59 a, 59 a′ in the lamellar linkage plate 58 ofthe actuating plate 54. The T-anchors 59 a, 59 a′ perform the functionof the claws 59, 59′. Pins, which are arranged on the actuating plate 54of the half diaphragms 51, 51′ and engage in the covers 55, 55′, form alinkage guide for the actuating plates 54. Said pins guide the actuatingplates 54, during the rotational movement thereof, about the center ofthe iris diaphragm 50, and thus increase the closing range of thelamellae.

FIGS. 12 to 14 show a further exemplary embodiment of the iris diaphragm50 having a simpler construction. In order to explain the mechanicalprocesses, a coordinate system will now be introduced. The X-axis ofthis coordinate system extends substantially along one arm 12. TheY-axis lies transversely thereto and points toward the center of thethrough aperture of the iris diaphragm 50.

FIG. 12 shows, by way of example, the first half diaphragm 51 in anexploded view. A substantial difference in the exemplary embodimentaccording to FIGS. 12 to 14 as compared with FIG. 6 is that the functionof the actuating plate 54 in the exemplary embodiment of FIGS. 12 to 14is realized by one of lamella 53 to 53″, specifically the lamella 53′.The fastening plate 56 of FIG. 12 is also firmly connected to the firstarm 12. Said fastening plate has three cut-outs 61, 61′, 61″, which openradially in the direction of the center of the through aperture of theiris diaphragm 50. Lamella pins 63, 63′, 63″ are placed in cut-outs 61,61′, 61″. Said pins are arranged substantially centrally on the lamellae53, 53′, 53″. The cut-outs 61, 61′, 61″ form a linkage guide along whichthe individual lamellae 53, 53′, 53″ can be moved toward the center ofthe through aperture. The lamella pins 63, 63′, 63″ are provided on bothsides of the lamellae 53, 53′, 53″. They engage, on one side, in thecut-outs 61, 61′, 61″ of the fastening plate 56 and, on the other sideof the lamellae 53, 53′, 53″, in cut-outs 65, 65′, 65″ of the cover 55.The cut-outs 65, 65′, 65″ of the covers 55 also extend substantiallytoward the center of the through aperture of the iris diaphragm 50.Lamella 53′ is rigidly connected to the actuating element 52 and has acorresponding projection for this purpose. The actuating element 52 isactuated along the Y-axis. Therefore, by means of the actuating element52, the second lamella 53′ can be moved in the direction toward thecenter of the through aperture. The semicircular lamellae 53 to 53″ eachhave a cut-out 64, 64′, 64″, 64′″ at their ends, which engage with thepins 63, 63′, 63″ of the other lamellae 53 to 53″. A mechanical couplingis therefore made between the first lamella 53 and the second lamella53′ (cut-outs 64, 64′) which, in turn, is connected to the third lamella53″ (cut-outs 64″, 64′″). The movement of the second lamella 53′ alongthe Y-axis causes actuation and displacement of the first and thirdlamellae 53, 53″. The linkage guides are configured to move each of thelamellae 53 to 53″ toward the center of the through aperture when thesecond lamella 53′ is displaced along the Y-axis. A contrary movement ofthe second lamella 53′ causes this movement to be reversed. The irisdiaphragm 50 opens.

The second half diaphragm is correspondingly symmetrically constructed.FIGS. 13 and 14 show the half diaphragms 51, 51′. It is apparent that,in a closed state of the electrosurgical instrument 10, the firstlamella 53 of the first half diaphragm 51 enters into a mechanicalconnection with the lamella 53″ lying opposed thereto. Here also, thereis a connection between the lamella pins 63, 63′, 63″ and the cut-outs64, 64′, 64″. The same applies for the third lamella 53″.

The coupling of the lamellae 53 to 53″ of the first half diaphragm 51 tothe lamellae of the second half diaphragm 51 is releasable. In theopened state of the instrument 10, the iris diaphragm 50 has a gap, bywhich the connected hollow organ can be separated from the instrument10. Therefore, in the closed state of the electrosurgical instrument 10,a ring of lamellae 53 to 53″″ is formed, comprising six lamellaeaccording to the exemplary embodiment of FIGS. 12 to 14. The individuallamellae 53-53′″ are each in operative connection with the adjacentlamellae 53-53′″. Taken together, a linkage guide is formed, whichenables a translation movement of the individual lamellae 53 to 53′″ inthe direction toward the center of the through aperture. Actuation ofthe actuating elements 52, 52′ is therefore transferred mechanically tothe individual lamellae 53 to 53′″.

According to the disclosed embodiments, the iris diaphragm 50 comprisesa first outer electrode arrangement or outer electrode and the sleeve 32comprises an inner electrode arrangement, specifically the sleeveelectrode 36. As FIG. 5 shows, these electrodes are arranged adjoiningone another. The sections of hollow organs clamped between the irisdiaphragm 50 and the sleeve 32 can be connected to one another by theseelectrodes. For this purpose, a corresponding HF current is applied tothe electrodes. The HF current causes coagulation of the tissue sectionssituated between the electrodes. To apply the HF current, theelectrosurgical instrument 10 has suitable conductor tracks andterminals. For example, the sleeve electrode 36 can be supplied via aconductor track within the sleeve actuating arms 55, 55′. A suitableconductor track for the iris diaphragm can be situated within the arms12, 12′.

Alternatively, the arms 12, 12′ and/or the sleeve actuating arms 53, 53′can be entirely or partially constructed from electrically conductivematerial in order to provide a suitable conductor track.

The individual lamellae 53 to 53′″ can comprise electrodes for applyingthe HF current and/or can be made from electrically conductive material.

Preferably, the base plate 13 and the removable section 13′ of the baseplate 13 is an electrical insulator. Thus, the conductor track of thesleeve electrode 36 is electrically insulated from at least theconductor track of the iris diaphragm 50.

In a further exemplary embodiment, the base plate 13 and/or theremovable section 13′ can comprise terminals and electrical conductortracks to supply the electrodes.

Exemplary embodiments with four and eight lamellae 53 to 53″″ have beendescribed. Other embodiments with different amount of lamellae 53 to53″″ are also conceivable (e.g., with at least four lamellae 53 to53″″).

The invention claimed is:
 1. A coagulation electrode, comprising: amounting ring; a plurality of lamellae mounted on the mounting ring,said lamellae being pivotable from an open state to a closed state, inthe manner of an iris diaphragm, to form electrode sections; a linkagering, which is arranged rotatable relative to the mounting ring andengages with guide members on the lamellae such that, on rotation of thelinkage ring relative to the mounting ring, the lamellae are pivotedfrom the closed state into the open state and vice versa, wherein themounting ring and the linkage ring are each configured in two parts suchthat they can be moved away from one another together with the lamellaemounted on the mounting ring and engaging with the linkage ring.
 2. Thecoagulation electrode of claim 1, wherein the linkage ring is dividedinto two parts, such that said ring comprises first and second linkagering sections that are movable separately from one another.
 3. Thecoagulation electrode of claim 2, wherein the first and second linkagering sections are movable by guide rods.